Rotary printing press



July 2, .1940. a. HANTJOPOULOS ROTARY PRINTINI? PRESS Filed July 2.9, 1938 0 R W n A H m: a M a w a: a 4. Y

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Patented July 2, 1940 UNITED STATES PATENT OFFICE Q 2,206,186 i v RorARY PRINTING PRESS George Hantjopoulos, New York, 1N. Y.

Application July 29, 1938,. Serial No. 221,916

6 Claims.

of the folder.

My experiments prove that, the press, in action, practically ignores every resistance, between tension and the pins of the folder.

Therefore, the whole load in a press, from tension is carried by the pins of the folder. therefore, the load was the invisible cause of breaking the pins, and damaging the press.

To eliminate the above stated wastedpaper, and damaging of the press, I invented differ ential circumference between inside and out side in either or both of impression and plates of cylinders, (larger inside, and smaller outside), to increase the strength of the paper, and remove pulling force from the edges of And also a difierential circumference between first pair of impression cylinders, and second pair of impression cylinders, to controlsheets and reduce tension, and by reducing tension,

I reduce the load on the pins of. the folder.

The invention is a printing press of the rotary type having printing plate cylinders, with the circumference of the central portion of said cylinders slightly larger than that of the ends of the cylinders, and. with the second cylinder slightly larger than the first cylinder of a unit.

Considerable trouble is continually experi enced in rotary presses, and, particularly, presses of the newspaper type. because of breakage of 0 the paper which causes waste, and this is caused by the fact that substantially the entire pull on the paper is through the pins of the folders, and this causes continuous breaking thereof. This causes a considerable loss in the running time of printing presses and an enormous waste of paper, and, furthermore, considerable time is lost through repairing broken pins.

The object of this invention is, therefore. to j eliminate the cause of the breakage of the paper of rotary printing presses, and thereby increase the capacity of the press, substantially eliminate waste, and also step up the speed.

the folder, or invisible causes,breaking the pins Another object is to provide means for re 5 lieving the tension at, or adjacent to, the edges of the paper of a rotary printing press by providing means for frictionally gripping the paper throughout the central part thereof.

A further objectis to providemeans for readily increasing the diameter and circumference of the printing plate rollers of rotary printing presses throughout the intermediate portions thereof. i

And a still further object is to provide. improvements in rotary printing presses which relieve and also distribute the strain of the paper and frictionally urge the paper through the press from intermediate parts thereof which are of a simple and economical construction.

With these ends in view the invention embodies a rotary printing press in which the intermediate portions of the plate cylinder asa semblage are of a slightly larger diameter than the ends, and in which the latter set of plate and impression cylinders is slightly larger than those of the other set when two sets are com bined in a unit.

Other features and advantages of the invention will appear from the following description taken in connection with the drawing, wherein:

Figure 1 is a diagrammatic view showing a sectionthrough a unit of a printing press with the parts indicated by single lines.

Figure 2 is a plan view of the unit shown in Figure 1 Figure 3 is a detail showing one of the printing plate cylinders of the press of the type shown in Figures l and 2.

Figure 4 is a similar view showing a cylinder ofa press of an alternate design.

Figure 5 is also a similar view showing a cylinder of apress of another alternate design.

Figure 6 is a detail in which the parts are exaggerated, showing that the latter set of cylinders is larger than the other set. I

In the drawing the improvementsare illustrated as they may be used, wherein numeral l indicates a roll of paper, numeral 2, a folder, numerals 3 and 4, printing plate cylinders, and numerals 5 and 6-, impression cylinders.

It will be understood that any number of units may be used in one press, and cylinders of any width may be used to accommodate presses of any width. The roll of paper, as indicated by the numeral 1, is generally located below the floor, and is fed upward through the first set of printing cylinders, however, for the purpose of illustrating this invention, the paper roll'is shown mounted at the end of the machine, and the rotation thereof is retarded by friction belts with weights in the pulleys at their lower ends, or any friction, holding or retarding means may be used. The paper, which is indicated by the numeral 7, passes upward over a roller 8, around a roller 9, and upward between the cylinders 3 and 5, and then downward around the cylinder 6 and upward between the cylinders 4 and 6.

The paper then passes upward over a roller it around another roller ll, another'roller l2 and over a cylinder 13, from where it passes down ward between pinch rollers it in the folder 2 Where it is gripped by the usual pins 15, that provide the pulling means for drawing the paper through the machine. 1

. The cylinders may be driven in any manner, however, they are generally geared together as shown in Figure 2, with the cylinders 3' and 5 geared together by gears l6 and ll, the cylinders 5 and 6 geared by gears l8 and I9, and the cylinders B and l by the gears 2i] and 2|. All of. the cylinders, therefore, rotate at a constant speed, and, therefore, in order to provide-a differential between the speed of the cylinders 4 and 6 and that of the cylinders 3 and 5, it is only necessary to slightly increase the diameters of the cylinders 4 and B.

In the machine illustrated, the printing plate cylinders 3 and a are provided with printing plates 22, 2'3, 24 and 25 on the cylinder 3, and plates .28, 27, 28 and 29 on the cylinder 4, and these plates are formed in two halves, with the halves secured to the cylinders which are of the same diameter and generally finished absolutely smooth and true. The impression cylinders 5 and 6, which are covered with blankets, are' also substantially round and uniform throughout their lengths.

These plates are shown in section in Figure 3, and the drawing, which is exaggerated, shows the plates 23 and 24 slightly larger than the plates 22 and 25, however, these plates may be formed and assembled on the cylinder with a gradual continual slope toward the center,- providing a slightly larger diameter throughout the intermediate part of the printing plate assembly than the diameter at the ends. The drawing illustrates the intermediate plates slightly thicker than the plates at the ends, however, in Figure 5, the

thickness of the plates, which are indicated by the numerals 39 and 3|, is tapered, and it will be understood that'the plates shown in Figure 3 may also be tapered in order to provide a larger diameter at-the center; or anymeans may be used for slightly increasing the diameter of the print ing plates at the center or throughout the intermediate part thereof so that the diameter is slightly larger in the central portion than at the ends, so that the paper is positively drawn by pulling on the center thereof instead of at the ends. It has been found by numerous experiments that with the engaging surfaces of the printing plates substantially parallel, thetension at the edges of the paper causes breaking of the paper. Therefore, byshaping the rollersin this manner, and thereby reducing the tension at the edges, the tension is placed upon the body of the paper throughout the central portion thereof, and the newspaper printing presses with the plate cylinders formed in this manner do not'break the paper, and waste is, therefore, substantially eliminated.

Figure 4 merely illustrates" an arrangement of a. three plate cylinder, with a central plate 32 slightly larger than the end plates 33 and 34,

however, it will also be understood that the central plate 32 may be parallel to the surface of the cylinder, and the end plates 33 andt l may be sloped or tapered slightly, or, as hereinbefore stated, these plates may be arranged in any manner in order to provide a plate cylinder assembly slightly larger at the center or throughout the intermediate portion thereof. These plates may also be formed by planing or grinding ma- 7 terial from the back thereof, or set with shims,

or assembled in any manner or by any means. I

Another important feature in the successful operation of newspaper printing presses has been found to be in an improved method of urging the paper through the press, as, in presses of this the central part of the paper with cylinders formed as hereinbefore described, and this has a tendency to urge the paper toward the folder, or even feed the paper through the machine. The paper is, therefore, positively gripped and fed or urged toward the folder by these last two cylinders, and this relieves the tension and also the load on the pins in the folder.

The increased diameter of the cylinder 4, or of the cylinders i and 6, is exaggerated in the drawing, as this is only about three thousandths of an 1 inch in the circumference, but this slight difference relieves the tension and actually draws the paper from the two former cylinders. The increased diameter of the cylinders at the center or through the intermediate portions is also very slight, the cylinders being about two or three thousandths of an inch larger at the center than at the ends.

To maintain the required differential in circumference and be the most beneficial it is essential that the following method should be used in installing the plates on the cylinders of a rotary printing press.

The interior end of an interior plate should:

be lowered carefully upon the cylinder, then it should be slid to its position, and when the other end of the plate reaches a heighth of two to three inches from the cylinder, it should be let drop on the cylinder with a knock, and next it should be turned sidewise to the head register, and then turn it off or back from the head register a little. The outside plate should be lowered andplaced on the cylinder carefully, with the same motion, but soundless.

It will be understood that other changes may be made without departing from the'spirit of the invention. One of which changes may be in the use of any other means for slightly 'increasing the diameter or circumference of the plate cylinders assembly or impression cylinders, another may be in the use of other means for increasing the diameter of the latter set of cylinders, and still another may be in the use of any other improvements in combination with these changes, or in the use of these changes in a press or apparatus of any other type. I

The construction will be readily understood from the foregoing description. In use the remainder of the press will operate in the .usual manner, and the printing .plates will be assem-.'

bled on their respective cylinders in their usual locations, however, the circumference at the center or throughout the intermediate portions thereof will be slightly larger than at the ends, and this increases friction at the centers of the cylinders, thereby placing the load or actually pulling the paper from the central part, and removing or relieving the tension or pulling force at the edges, and, in doing this, and also in providing the differential in the traveling or surface speed by increasing the surface speed of the last set of cylinders makes it possible to minimize breaking the sheet and wasting the paper.

Having thus fully described the invention, what I claim as new, and desire to secure by Letters Patent, is:

1. A rotary printing press of the type having printing plate cylinders in combination with impression cylinders, in which the diameter of the cylinders at the center is slightly larger than the diameter at the ends thereof.

2. A rotary press of the type having printing plate cylinders in combination with impression cylinders, in which the diameter of thesaid cylinders is slightly larger throughoutthe intermediate portions thereof than at the ends.

3. A rotary printing machine, as described ter thereof with the engaging means being gradually relieved toward the edges so that the edges are substantially free.

5. The art or process of evenly distributing the tension on paper traveling through rotary printing presses, which comprises increasing gripping throughout the longitudinal center of the paper passing between the printing plate cylinders and the impression cylinders.

6. In a rotary printing press of the type having printing plate cylinders and impression cylinders, in which each printing plate cylinder is in continuous contact with a compression cylinder during printing operations, and in which the continuous contact between the printing and impression cylinders provides friction feeding means continuously feeding the web through the press; means insuring constant tension on the web during the printing operation comprising a printing plate cylinder of a very slightly increased diameter for the last impression of the press.

GEORGE HANTJOPOULOS. 

